Seamed joints



Sept. 9, 1969 M.- J. PHILLIPS 3,466,661

SEAMED JOINTS 'Filed Dec. 28, 1967 2 Sheets-Sheet l FIG.3

Sept. 9, 1969 Filed Dec. 28, 1967 M. J. PHILLIPS SEAMED JOINTS 2 Sheets-Sheet 2 United States Patent 3,466,661 SEAMED JOINTS Melville John Phillips, Epping, New South Wales, Australia, assignor to Rheem Manufacturing Company, New York, N .Y.

Filed Dec. 28, 1967, Ser. No. 694,251

Claims priority, application Australia, Jan. 6, 1967,

16,182/67 Int. Cl. B21d 51/28; F16l 41/00 US. Cl. 113-1 Claims ABSTRACT OF THE DISCLOSURE The invention is an improvement in double seam joints, e.g., between the rim of an aperture in a metal drum head and the adjacent end of a flange located in the aperture. According to the invention the frictional adhesion normally achieved by clenching the seamed joint is substantially improved by providing spaced indentations around the joint by indenting one face of the joint during clenching.

Summary This invention relates generally to sheet metal drum heads and to an aperture in such a head in which is secured a flange adapted to receive and retain a closure plug.

For convenience, the invention will be described with the drum disposed so that the drum head is approximately horizontal and uppermost.

The flange ordinarily consists of an upright cylindrical portion stifiened around its upper edge by curling and secured near its lower edge by a curling process to the inner edge of the aperture in the drum head.

The invention is particularly concerned with the joint between the inner edge of the drum aperture and the adjacent edge of the bottom of the flange. Ordinarily, the joint is formed by clenching the two edges tightly together in a double seam.

It is found in practice however that, in use, when a large torque is applied to secure a plug in the flange or to withdraw a plug from the flange, the flange curl in the double seam may rotate relative to the drum head curl.

The principal object of the present invention is to modify the conventional joint so as to prevent substantially this relative rotation.

Another object of the invention is to provide a suitable tool for forming the joint according to the invention.

In one form of the invention the conventional joint is modified by providing circumferentially spaced radial indentations in the outside surface of the lower flange curl or in the outside surface of the drum aperture curl. In either case, in a conventional clenching operation, the indented surface on one component in the double seam causes a corresponding indentation in the adjacent surface of the other component so as to lock the two curls together more securely than when there are no indentations.

Drawings FIGURE 1 is a typical sectional elevation of a drum head, flange and plug;

FIGURE 2 is an inverted plan view of the drum head showing the indentations formed in the curl of the flange;

FIGURE 3 is an enlarged fragmentary view in section on the line 33 of FIGURE 2;

3,466,661 Patented Sept. 9, 1969 lice Description In FIGURE 1, 2 is-the drum head, 3 is its aperture, 4 is its curl, 5 is the flange, 6 is its upper stiffening curl and 7 is its lower curl. Either the lower surface of 7 or the upper surface of 4 is provided, for example, with spaced radial indentations 1 so that during clenching together of the surfaces, the indentations are transferred to the adjacent portion of 4 or 7. The flange 5 is normally provided with internal threads 5A.

In FIGURES 4 and 5, 14 is an upper platen supporting an upper punch 15 and 16 is a lower platen supporting a retainer or housing 17. Within the housing 17 is a blade support ring 18 and an anvil 19. The anvil is provided with a curling groove 20 (FIGURES 4 and 5) in its upper surface. At spaced intervals around the anvil radial slots 21 are formed. These receive the respective blades 22 which rest on the ring 18. The upper edges 23 of the blades are designed to provide appropriate indentations 1. The flange 5 is located between 15 and 19 with the joint 4, 7 in register with 20. The double seam joint between the flange and the drum aperture is completed by moving the punch 15 into engagement with the anvil. The curling groove 20 is appropriately shaped to ensure that the relevant parts are securely clenched together and simultaneously during clenching the spaced blades 22 indent the adjacent surface of one of the components 7 and cause corresponding indentations in the adjacent surface of the other component 3.

In an alternative construction (not shown) grooves corresponding to the blade indentations may be formed in the undersurface of the top punch to match the indentations so that the distortion caused by the blades may be carried through all the thicknesses of the clenched joint. This helps to achieve a more positive lock between the adjacent surfaces instead of a frictional one. In another alternative construction the position of the blades and grooves may be reversed, for example, by providing indenting blades on the top punch and corresponding relief grooves across the curling groove.

What I claim is:

1. A seamed joint of the type described between the edge of a drum head opening and one end of a drum flange located in the opening wherein circumferentially spaced indentations are formed in at least one exposed surface of the seamed joint during clenching of the joint.

2. A process for making a seamed joint of the type described between the edge of a drum head opening and one end of a drum flange located in the opening including the steps of preparing the seamed joint, clenching the jointand simultaneously forming spaced indentations.

3. Apparatus for making a seamed joint of the type described between the edge of a drum head opening and one end of a drum flange located in the opening including a first platen, a punch secured to the platen and having a clenching surface, a second platen, a housing mounted on the second platen, an anvil mounted in the housing, having an operating surface in register with the clenching surface of the punch, circumferentially spaced slots around the operating surface of the anvil, a blade mounted in each slot, a curling groove around the operating surface of the anvil and intersecting the blade edges and a recess in the punch or the anvil to receive the flange, means being provided for allowing movement of the punch and anvil towards or away from each other.

4. Apparatus as in claim 3 wherein the clenching surface of the punch has spaced grooves, each in alignment with a corresponding anvil blade.

5. Apparatus as in claim 4 modified by providing indenting blades on the punch instead of the anvil and corresponding grooves instead of blades across the curling groove of the anvil.

2,916,311 12/1959 Keplinger 22039 3,149,744 9/1964 Pentesco 22039 RONALD D. GREFE, Primary Examiner US. Cl. X.R. 

